Valve stem umbrella seals...
November 5th, 2012, 08:28 AM
#1
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Join Date: Jul 2009
Posts: 21
Valve stem umbrella seals...
Since my 455 with Ga heads have been sitting a while, I am lapping in the valves to avoid any valve sealing problem upon restart. I have purchased new valve seals and have installed a couple, but they are a tight fit and do not easily slide up and down the stem.
Are the seals supposed to slide easily on the stem? I have never replaced valve seals before and I really don't know what to expect...
Any observations or opinions? Thanks in advance!
Rockettruck (Randy Wickham)
Wheelersburg, Ohio
Are the seals supposed to slide easily on the stem? I have never replaced valve seals before and I really don't know what to expect...
Any observations or opinions? Thanks in advance!
Rockettruck (Randy Wickham)
Wheelersburg, Ohio
November 5th, 2012, 11:39 AM
#2
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Join Date: Sep 2011
Location: Plano, TX
Posts: 1,847
Umbrella seals don't move. They get pushed up the stem on the first valve opening then hang there. The umbrella just stops oil from splashing directly onto the stem.
Don't even need to worry about installing them in a particular place. Slide in the valve, slide the umbrella all the way down, done! The first time cranking the engine will bump them around.
Don't even need to worry about installing them in a particular place. Slide in the valve, slide the umbrella all the way down, done! The first time cranking the engine will bump them around.
November 5th, 2012, 11:45 AM
#4
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Join Date: Feb 2008
Location: Plano, TX
Posts: 11,798
And to be more exact, "The first time cranking the engine will bump them" to their final position.
I replaced the ones in my engine and was quite amazed at how well these work, compared to the ones that are secured to the head and wear out in the valve stem hole.
I replaced the ones in my engine and was quite amazed at how well these work, compared to the ones that are secured to the head and wear out in the valve stem hole.
November 5th, 2012, 11:50 AM
#5
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Join Date: Sep 2010
Location: The Hudson Valley
Posts: 21,183
Interesting topic - I have wondered about this.
Prior to dealing with Olds engines, I had only seen the other type of rubber seals that clamp to the valve guides and moe or less squeegee the valve shafts.
Which really works better - umbrella, or rubber?
Anybody else have experience with this?
- Eric
Prior to dealing with Olds engines, I had only seen the other type of rubber seals that clamp to the valve guides and moe or less squeegee the valve shafts.
Which really works better - umbrella, or rubber?
Anybody else have experience with this?
- Eric
November 5th, 2012, 07:28 PM
#6
Registered User
Join Date: Feb 2008
Location: Plano, TX
Posts: 11,798
I think they both have pros and cons.
The stationary seal has the advantage of providing a small about of additional air seal in the event of excess valve guide wear. On the other hand, the hole around the valve stem wears and then lets oil pass through. This gets worse as the seal hardens with age.
The 70s-90s Ford 2.3L has the stationary seal and they usually requires seal replacement about every 10 years due to oil leakage and burning. I have done it twice even after using "premium" seals from Felpro.
The floating umbrella seals will last until they just deteriorate and fall apart from extreme age. On the other hand, I do not think they allow as much oil to contact the valve stem. Someone set me straight on this assumption...
The stationary seal has the advantage of providing a small about of additional air seal in the event of excess valve guide wear. On the other hand, the hole around the valve stem wears and then lets oil pass through. This gets worse as the seal hardens with age.
The 70s-90s Ford 2.3L has the stationary seal and they usually requires seal replacement about every 10 years due to oil leakage and burning. I have done it twice even after using "premium" seals from Felpro.
The floating umbrella seals will last until they just deteriorate and fall apart from extreme age. On the other hand, I do not think they allow as much oil to contact the valve stem. Someone set me straight on this assumption...
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